Lifting jack



Aug. 26, 1952 J, F PALKA 2,608,382

LIFTING JACK Filed April 27. 1948 /Z' /Z .Z5 JNVENTOR. Jaep/.zPaZ/ia,

l of and beyond leg 22.

shifting motion, without obstruction from plate I0, as is seen in Fig. 2.

The upper end of leg extends above said plate II), plates I3 and wings I4, and provided therein is a substantially square block 24, which is welded or otherwise firmly attached therewithin. Integrally formed with said block 24 and seated upon the upper termination of leg 20 is a closure member comprising an annular head 25 which is provided with a bore for receiving races 26 with a ring of ball bearings 2'I interposed therebetween. Passed through said block 24 and head 25 is post 28 with which said ball bearings 21 contact and facilitate its rotation. Cotter pin 29 passed through post 28 is in contact with the lower end of block 24 for preventing upward shifting movement of said post 28. Collar 33 rigidly affixed to said post 28 by means of pin 3| rests upon the uppermost race 26 and prevents the downward longitudinal shifting of said post 28. If preferred, said collar 3l) may be rigidly afxed t0 the uppermost race 26 for rotating the latter upon ball 'bearings 21 when a rotary movement to post 28 is imparted.

The upper end of said post 23 which reposes within block 2li, races 26 and collar 33 is smooth. Thel remaining portion of said post 23, below cotter pin 29 is threaded. Cross brace 32 affixed to the free edges of the sides of said leg 20, adjacent the lower end of the latter, prevents outward flexing of'post 28. Said post 28 is in ka spaced relation with the sides and with the central portion of said leg 23. The space between said post 28 and the central body portion of said leg 23 accommodates said bolt 2|.

By virtue of the above described arrangement 4post 28 is capable of rotary movement in either direction, being guided in that movement by block 2 4, but is incapable of bodily shifting in lan upright direction, being prevented from that said leg 20 and upon post 28, when the latter rotates. Aand laterally extending from the fourth open Integrally formed with said block 33 face thereof is extension 34 which extends out This extension 34 is for the purpose of engaging the underface of any object to be lifted, such as an automobile bumper preparatory to the shifting of saidblock 33 and extension 34 by the action of post 28 for lifting the engaged object.

The upper end of post 23 which extends above collar 33 is provided with a transverse bore 35 for interchangeably receiving therewithin the longer or the shorter end of L-shaped handle 35. Thumb screw 3l entering a threaded bore made-in the upper end of post 23 in a longitudinal direction therewith, is driven in a transverse relation with bore 35 for rigidly engaging and .clamping the longer or the shorter end of said'handle` 3B when inserted in said bore 35.

Rigidly mounted to thel lower ends of legs I2 Yand 20 are'supporting plates 38, which Vare at an incline with relation to the longitudinal axis of said legs in order that the same may conform to and rest upon horizontal plane of the ground upon which the jack is intended to be supported when said legs are angularly shifted into an open position, as seen in Figs. 1 and 2.

Ailixed to leg 20, substantially at a central point thereof, is a pair of chains 39, each of which is connected by its opposite end with each leg I2, for the purpose of limiting the outward shifting movement of leg 20 and legs I2 with relation to each other as said leg 20 is shifted away from the plane of said legs I2.

When handle 33 is aixed by its longer end to post 28 by means of thumb screw 31, the shorter end thereof, directed upwardly constitutes means whereby post may be rotated, when said legs I2 and 20 are in an open position, as seen in Figs. 1 and 2. The rotation of post 28 in either direction shifts block 33 and extension 34 in either direction, for the purpose of lifting the object engaged by said extension 34 or of permitting the same to shift Vdownwardly, depending on the direction to which said post 28 is caused to rotate by means of said handle 36.

To fold the jack into a comparatively compact bundle, as illustrated in Figs. 3 and 4, legs I2 are shifted toward each other, on rstv-directing arms IS into an upward direction in order that they may fold. Thereupon leg 20 is shifted towards the plane of said legs I2, until the former assumes a substantially co-planar relation with said legs I2. When said legs I2 and 2i! are folded as aforesaid, handle 36 may then be inserted by its shorter end within post 28, with its longer end downwardly depending. In that position of handle 36, as seen in Fig. 3, the shorter end of said handle 36 constitutes a bar which may be manually grasped for carrying the folded jack.

In a folded position of legs I2 and `20, chains 39 loosely hang therefrom, Vas is seen in Fig. 3.

Although the tripod arrangement of the jack disclosed herein permits i'lrm support of the jack upon the ground while in use, I do not exclude the possibility of the use of leg 20 alone, on

first disconnecting the same from wings VI4 von removing nut 23 and bolt 2I from said wings I4 and from the sides of leg 20. This will re- Ylease leg 23 from the tripod arrangement of the jack, after of course disconnecting chains 39 from said leg 20. Leg 20 thus released from the tripod assembly may still be used as ajack, because post 28, block 24, races 26, cotter pin 23 and collar 33 would still remain in the assembly of said leg 20 for shifting block 33 and extension 34 for lifting action.

Block 24 maintains post 28 centered withl relation to leg 20. The faces of block 33 being in contact with the inner faces of the sides of said leg 20, prevent rotary shifting movement of said block 33 and its extension 3d when post 28 rotates, but permit longitudinal sliding movement thereof with relation to leg 20 and upon post 423. The outer free edges of the sides of said leg 20 dene a recess through which extension 34 extends and within which the same shifts.k Cross Vbrace 32 prevents the lower end of post 28 to spring out of the said recess, due to any centrifugal ilexingofsaid post 28 when aswift rotary movement is imparted thereto by handle 36,

therebyals'opreventing said block 33, from shift- 'ing outwardly of the' leg through said recess.

When extensionv 34 is in engagement'withthe distributed from said extension 34 andpost Y23 to collar 3Iland the uppermost'race 26.4 Due to the weight strong frictional contact betweenjjsaid collar 30 and the uppermost race 25 is engendered, if they are not otherwise rigidly connected, permitting the rotation of said uppermost race 26 on rotating said collar 30 with post 28 by means of handle 36. Ball bearings 21 supporting said uppermost race 26 permit easy rotation of the latter when post 28 is rotated.

While there is described herein a preferred embodiment of the present invention, it is nevertheless to be understood that minor changes may be made therein without departing from the spirit and scope of the invention as claimed.

What I claim as new is:

1. A lifting jack comprising a head plate, a pair of legs, pivot means connecting each of said legs to said head plate, said legs angularly shifting along a plane substantially in parallel alignment with said plate into an open or folded position, a third leg pivotally connected to said head plate at a point intermediately of said i-lrst named legs, said third leg angularly shifting into an open or folded position on a plane which is substantially in a perpendicular relation to the plane upon which saidrst named legs shift, a lifting member supported by said third leg for longitudinal shifting movement, means for imparting a shifting movement to said lifting member, a pair of rigid arms pivoted together at one end, said arms being pivoted at their opposite ends to each of the pair of legs intermediate the ends of said legs, and a pair of flexible members connected at one end to the third leg, one of said exible members being connected at its opposite end to one of the pair of said legs and the other flexible member being connected at its opposite end to the other leg of the pair of legs.

2. A lifting jack comprising retaining means and bracing means, said retaining means including an elongated member and having opposite sides spaced apart, a threaded post extending lengthwise of said member between the sides thereof, an element threaded on said post and engaging said opposite sides, means on one end portion of said elongated member and overlying the threaded post for holding said post in said elongated member, a journal head secured to the opposite end portion of said elongated member and having the post extending therethrough, means connected with the extended portion of the post for rotating said post, said bracing means including a pair of legs, and means connecting the retaining means and bracing means together including a head member extending on each side of the elongated member and having wings connected therewith portions of which embrace opposite sides of the elongated member, and pivots connected with the wings of opposite sides of the elongated member about which the legs swing relative to said elongated member.

3. A lifting jack comprising retaining means and `bracing means, said retaining means including an elongated member U-shaped in cross-section, with opposite sides spaced apart, a threaded post extending lengthwise of said member between the sides thereof and substantially throughout the length of said member, an element threaded on the post between the sides of the member and projecting out of the member for supporting a device thereon, means on one end portion of said elongated member and overlying the threaded post for holding said end portion of the post in said elongated member, a journal headr secured to the opposite end portion of said elongated member and having the threaded post extending therethrough and journaled therein, means connected with the extended portion of the post for rotating the post relative to the journal head, said bracing means including a pair of legs, and means connecting the retaining means and bracing means toegther including a head member extending on each side of the elongated member and having wings connected therewith embracing opposite sides of the elongated member, and pivots connected with the wings at opposite sides of the elongated member about which the legs swing relative to said elongated member.

4. A lifting jack comprising retaining means and bracing means, said retaining means including an elongated member and having opposite sides spaced apart, a threaded post extending lengthwise of said member between the sides thereof, an element threaded on said post and engaging said opposite sides, means on one end portion of said elongated member and overlying the threaded post for holding said post in said elongated member, a journal head secured to the opposite end portion of said elongated member and having the threaded post extending therethrough, means connected with the extended portion of the post for rotating saidpost, said bracing means including a pair of legs, means connecting the retaining means and bracing means together including a head member extending on each side of the elongated member and having wings connected therewith portions of which embrace opposite sides of the elongated member, a pivot connected with the wings at opposite sides of the elongated member to provide for relative swinging movement between the legs and said elongated member, and additional pivot means connected with the legs and mounting the legs on the connecting means for swinging movement laterally in opposite directions relative to each other.

JOSEPH F. PALKA.

REFERENCES CITED The following references are of record` in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,134,581 Barret Apr. 6, 1915 1,424,952 Townsend Aug. 8, 1922 1,812,967 Long July '7, 1931 2,043,479 Greiman June 9, 1936 2,458,961 Snyder Jan. 11, 1949 FOREIGN PATENTS Number Country Date 404,650 Germany 1 Oct. 22, 1924 637,310 France Apr. 27, 1928 

